1. Field of the Invention
The present invention relates to a recording medium, a recording method, a recording program, and a recording medium having the recording program recorded therein. The present invention is applicable to a DVD (digital versatile disk), for example. According to the present invention, the address of management information is identified with reference to a management table recorded in a fixed area of the optical disk so that a file of still pictures other than moving pictures can also be recorded by selecting a format for the management information to be recorded in combination with the file on the basis of the attribute of the file. Thus the information recording area on an optical disk can be utilized more effectively and desired data can be searched more quickly.
This application claims the priority of the Japanese Patent Application No. 2002-132239 filed on May 8, 2002, the entirety of which is incorporated by reference herein.
2. Description of the Related Art
Conventionally, there are available DVDs as large-capacity optical disks including writable DVDs (digital versatile disk) such as a DVD-R (DVD-recordable), DVD-RW (DVD-rewritable) and DVD-RAM (DVD-random access memory). Of these DVDs, DVD-R and DVD-RW having video data recorded therein in a format complying with the DVD video format can be reproduced by a reproduce-only DVD player or a computer to reproduce the video data.
FIG. 1 shows a chart explaining the DVD video format-based logical format of an optical disk. As shown in FIG. 1(A), the optical disk logically formatted according to the DVD video format has an information recording area thereof divided into a zone called “lead-in” at the innermost circumference thereof, a data zone and a zone called “lead-out” at the outermost circumference. The optical disk will have desired video data or the like recorded to the data zone thereof.
As shown, the data zone consists of a UDF (universal disk format) area (file system area) A1, VMG (video manager) area (DVD management information area) A2 and a real-time data recording area A3 in this order from the lead-in zone. The UDF and VMG areas are provided to record management information used to manage files of video data recorded in this optical disk. Of these UDF and VMG areas, the VMG area A2 is directed to a DVD player and will have recorded thereto TOC information (table of contents) used for management of all video data recorded in the real-time data recording area A3. On the other hand, the UDF area A1 is directed to a file management by a computer, and will have recorded thereto management information used for management of all the video data recorded in the real-time data recording area A3 in a format compatible with the file management system of the computer.
As shown in FIG. 1(B), the real-time data recording area A3 is a program area where real data are to be recorded, and will have video data recorded therein in units of VTS (video title set; will be referred to simply as “title” wherever appropriate hereunder). It should be noted that a maximum of 99 VTSs can be provided. It is also important to note that as shown in FIG. 1(C), the “VTS” is composed of VTSI (video title set information), VTSM VOBS (video object set for the VTSM), VTSTT VOBS (video object set for titles in a VTS), and VTSI BUP (backup of VTSI) in this order. VTSTT VOBS will have recorded thereto MPEG (Moving Pictures Experts Group)-2-formatted video data as real video data, VTSI will have recorded thereto the address information etc. for management of the video data composed of real data, and VTSM VOBS will have a title menu of the video data recorded thereto. It should be noted that VTSM VOBS is an option and VTSI BUP is a backup of VTSI.
When the above optical disk is accessed by a computer, a desired file can be searched based on UDF for reproduction. When the optical disk is accessed by a DVD player, a desired file can be searched based on VMG for reproduction. Namely, UDF is supported by the file management system of the computer to manage video data recorded in the optical disk, while VMG is supported by the DVD player to manage video data recorded in the optical disk.
Video data is written to such an optical disk by either an incremental recording method (will be referred to as “INC method” hereunder) or restricted overwrite method (will be referred to as “ROW method” hereunder). The INC method is intended for sequential recording of video data, while the ROW method is applied to an overwritable optical disk. In the ROW method as well, however, video data which are to be recorded to a fresh (unrecorded) area will sequentially be recorded. In these INC and ROW methods, an RMA (recording management area) formed along the inner circumference of the lead-in zone provides an area management such as padding (will be described in detail later) or the like.
FIG. 2 shows a chart for explaining the ROW-based recording procedure. In the ROW method, a lead-in, UDF and VMG areas, and areas for recording the leading titles VTSI and VTSM VOBS are reserved by padding as shown in FIG. 2(A). It should be noted that the “padding” refers to a process for reserving an area by recording there dummy data such as null (zero) or the like.
In the ROW method, when these areas are reserved, video data are sequentially recorded to define a VTSTT VOBS of real data as shown in FIG. 2(B). Upon completion of recording the real data under one title, a VTSI BUP area is defined, and padding is done for securing recording areas for subsequent titles VTSI and VTSM VOBS, as shown in FIG. 2(B). Then, defining VTSI and VTSM VOBS areas for recording the real data will be repeated again from the beginning as shown in FIG. 2(C). Thus, one VTS is recorded in the optical disk by the ROW method.
In the ROW method, for continuously recording a next title, real data are recorded following a padded area composed of a preceding VTS to define VTSTT VOBS and VTSI BUP areas, and then padding is done for securing subsequent titles VTSI and VTSM VOBS, as will be known from FIG. 2(D). Subsequently, areas are defined for titles VTSI and VTSM VOBS as shown in FIG. 2(E) to thereby record successive VTSs to the optical disk as shown in FIG. 2(F). In the ROW method, for successively recording titles, similar padding is done to record VTSs sequentially.
On the other hand, in an optical disk having such VTSs sequentially recorded therein to define a real-time data recording area, the ROW method defines UDF and VMG areas by finalization, and then lead-in and lead-out as shown in FIG. 2(G) to thereby establish compatibility with a read-only optical disk. It should be noted that the UDF and VMG areas are defined by producing UDF and VMG data from the VTSI and VTSM VOBS title data and recording the-data to an inner-circumferential leading area by padding.
In the Japanese laid-open patent Publication Nos. 2002-063765, 2001-148166 and 2002-56609, it is proposed to record the top address of VTSI corresponding to a management table formed along the inner circumference of an optical disk correspondingly to recording of a title, manage the program area according to the management table to record a file of moving pictures and thus make each title accessible with reference to the management table even in a step before the finalization.
It is conceivable that such an optical disk is played in place of the magnetic tape in a portable video recorder. In this case, since the conventional video tape recorder can record moving pictures as well as still pictures, such an optical disk for use with the portable video disk recorder should also desirably be capable of recording still pictures other than moving pictures.
Note that in the aforementioned format, no consideration is given to such a file recording and hence it will be necessary to hold still pictures or the like in a memory and record them to another recording medium.
For such a file recording, it is desired that the information recording area can be utilized more effectively and a desired one of recorded files can be searched more quickly.